Add a more descriptive tooltip to the CVC field on the WooCommerce order form credit card fields

functions.php

<?php
//add tooltip to cvc field
function custom_credit_card_fields_cis_cc ($cc_fields , $payment_id){
	$cc_fields['card-cvc-field'] = str_replace('<p class="form-row form-row-last">','<p class="form-row form-row-last" title="3-digit security code usually found on the back of your card. American Express cards have a 4-digit code located on the front.">',$cc_fields['card-cvc-field']);
	return $cc_fields;
}
add_filter( 'woocommerce_credit_card_form_fields' , 'custom_credit_card_fields_cis_cc' , 10, 2 );